Remember, Walter was direct cooking over an open pit where mopping was part of his fire control.
For what it is worth, in many people's opinion, brisket is too big and thick for a marinade to penetrate deep enough to be significant. It is enlightening to me that you have found it works for you.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle